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[ Section Vaginatae page. ] [ Amanita Studies ] [ Keys & Checklist/Picturebooks ] Amanita coacta Bas"Felted Volva Ringless Amanita"
Technical description [ revision of N. Menolli Jr. et al. (2009), PDF 341 KB ] BRIEF DESCRIPTION: This description is taken from the original description of Bas (1978). The cap of A. coacta is 40 mm wide, umber in the center and pallid in marginal grooves, concave with or without a very slight umbo, with a sulcate-striate margin (extending to 50% of the radius). The volva is present as a few irregularly shaped, paler gray-brown felted, thin patches around the center of the cap. The gills are free, crowded, fairly broad, and white. The short gills are very scarce and truncate. The stem is 70 x 3 mm, tapering upward, without a bulb, exannulate, and white. The flesh is white and unchanging. The volva is up to 10 mm high at the base of the stem and felted-submembranous. According to the original description, spores of A. coacta measure 8.5 - 10.0 x 6.5 - 7.5 µm, and are broadly ellipsoid to ellipsoid. Clamps are absent at the bases of basidia. In the recent revision of the species by Menolli et al. (link to PDF is above), the spore measurements provided included two typographical errors. Dr. Menolli has permitted the editors to provide the corrected measurements here: "[340/17/16] (7.2-) 8.7 - 10.0 (-11.2) × (6.2-) 7.5 - 8.7 (-10.0) µm, (L = 8.7 - 10.0 µm; L’ = 9.5 µm; W = 6.8 - 8.4 µm; W’ = 7.8 µm; Q = (1.12-) 1.15 - 1.33 (-1.40); Q = 1.17 - 1.30; Q’ = 1.22)." Unpublished results of Wartchow et al. including spore data from a study of the type of A. coacta follow: [219/7/6] (6.4-) 7.2 - 11.0 (-11.5) × (4.5-) 5.3 - 8.3 (-8.5) µm, (L = 8.7 - 9.2 (-9.4) µm; L' = 9.0 µm; W = 6.4 - 7.1 µm; W' = 6.7 µm; Q = (1.14-) 1.19 - 1.56 (-1.69); Q = (1.28-) 1.31 - 1.37; Q' =1.33). [ For the meaning of the variables that do not usually appear on a "brief" description page, go here. ]This species was originally described from material collected in secondary rain forest (Manaus, Amazonas, Brazil) by Dr. Rolf Singer. -- R. E. Tulloss & L. Possiel Photographs: Courtesy Dr. Nelson Menolli Jr. (São Paulo State, Brazil). [ Section Vaginatae page. ] [ Amanita Studies ] [ Keys & Checklist/Picturebooks ] Last changed 26 October 2009. |
